VP44 Troubleshooting

[lberch]

First time poster, appreciate all the info exchanged here.

2001 2500 ETH (six speed) 245HP (I have owned the truck since new - June of 2000)

I think the current (subject) VP was installed by me around 2003??? and is the second replacement pump on this engine.

I have always changed fuel filters and  "check" lift pump pressure with a mechanical gauge which is anywhere from 6 PSI WOT to 12-14 PSI (25 second no start check).  I have a FASS DDRP installed (2011), (new overflow valve and fuel drain valve installed recently.

So......I am here looking for a little help

I have had an intermittent dead pedal about one year now.....It has progressively gotten worse over time (more frequent).  About two months ago I had a first time extended crank start maybe 4-5 second delay.  Unusual part about this new issue was that it would only have the delayed start in my driveway on a slight up incline.  If I turned the truck around (inclined down) it started normal (immediately) and when it was on level ground it also started normally.  I continued to drive the truck and decided to replace the fuel filter and check the pressure.....all seemed normal so I did some reading and decided to change the overflow valve and gaskets and tighten the fuel return banjo on the back of the head.  All seemed good for a few weeks and my "incline" delayed start issue was gone also.  Few more weeks later I started it one morning and it immediately started but oscillated up and down in RPM for a say 10 seconds.  Drove the truck and power was really low and dead pedal would come and go as well as now the engine sounds like its "detonating" engine sounds like a bucket of bolts.  Engine has a totally different (louder) engine noise than normal.  Did some more reading and I have been driving around with a clear hose under my wipers and my mechanical fuel pressure gauge for three weeks now.  No air in the system and FP is normal.   I even ran new hoses from the bed to the transfer pump and back to 5 gal of fresh diesel in a can and no change.  Also thought I may have a bad batch of fuel so I drained the tank and refilled with fresh good fuel and again....no change.

The only code it has ever thrown is P0122 APPS.  I did the "blue chip" APPS troubleshooting and I am fairly confident its not the APPS.  I am starting to believe it is either fuel valve solenoid (between the six distribution valves) or the advance solenoid or the computer (PSG) on top of the VP. I want to believe its the fueling solenoid as I have no timing codes set. But if the PSG commands XX fuel and correspondingly fires the fueling solenoid I don't think its getting any feedback as I don't think it measures flow?

The questions I have are:

1. Can the PSG (computer), Fueling solenoid and advance solenoid be individually tested? 

2. If the PSG is bad I already know if it gets replaced the pump has to be calibrated on a Bosch EP815 test stand.

3. If I can find and replace either solenoid will I get away without needing calibration?

4. Could it be the timing piston or another mechanical issue inside like a clogged mini screen?

This is driving me nuts as I like many, can't stand paying $1,250 for an exchange VP44

Any help or suggestions will be appreciated.

Thanks in advance, Leo

 

[Me78569]

1. No

2. not sure what your question is

3. I supposed you could , but I REALLY doubt you will find the solenoid

4. Typical failues at timing piston failures

 

Does the truck smoke white when it stumbles? White smoke typically means a timing piston failure, but you would almost always see a po216 code.

 

Does the p0122 code still show?  Have you cleared codes and driven it? Does the code come back?  Why don't you think it is the apps?

 

Dead pedal + a Apps code makes me really think the apps is dead.  

[dripley]

#2 You cannot just replace the computer on the VP. At least that is what I have been told. Even if i was lied to with the age of the pump I would want the all redone.

[Mopar1973Man]

There is no way to change the PSG without a Bosch 815 calibration bench which is a very spendy tool. So if your going to replace the VP44 your going to replace the entire thing. As for your fuel pressure it's way too low. Minimum side should be no lower that 14 PSI your dropping to 6 WOT this is very damaging.

If there was a timing piston problem of any sort there would of been a P0216 code. Your issues could be cause from two different thing one being AC noise from the alternator and two being you low fuel pressure.

[lberch]

thanks for the replies

No smoke at all not even a puff of black or white not at idle not during dead pedal not any at all

yes #2 above is more of a statement than a question....

I drove around for weeks with both a digital volt meter and an analog volt meter connected to the output pin of the APPS.  Always a smooth progression from .5v (idle) to 4.5v (wot).  When dead pedal occurred voltage still smoothly followed my foot and never jumped or dove or was erratic at all.  So that's why I don't think its the APPS

I need to pull the battery power this weekend and kill the 0122 code and see what happens.

I never have had more than 10 psi fuel pressure going down the road.  Not with a brand new carter or when the Fass was new.  I hear ya on FP though......my pressure is at the VP not the output of the pump.

How do I check if I have AC interference from the alternator?  Do I disconnect the alternator and just run on batteries for a short while?

I may have a lead on the solenoids over in the UK but yes they would not be an easy acquisition....

thanks for the help guys!

[dripley]

I agree with Mike on the fuel pressure. Most of us here get our fuel pressure readings after all the filters. Mine is tapped in between the the filter canister and the VP. I see 19 at idle and 16 at wot. The carter pump is never going to see this kind of pressure. There is a lot of good reading here about all of that. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system

[Mopar1973Man]

1 hour ago, lberch said:

I need to pull the battery power this weekend and kill the 0122 code and see what happens.

Won't happen. You can leave it disconnected for years and never clear those codes. Need a coder reader to erase the codes.

 

 

 

 

1 hour ago, lberch said:

I never have had more than 10 psi fuel pressure going down the road.  Not with a brand new carter or when the Fass was new.

Which FASS do you have? If it a factory replacement and still using all the junk stock fuel lines you need to upgrade. Everything from the pick up in the tank to the banjos on the VP44 is restrictive.

Edited January 7, 2016 by Mopar1973Man

[lberch]

I have the DDRP 2011 vintage (small replacement pump installed where the carter was.

All other lines and hoses are stock.

Understand need an OBII scan reader to reset - thanks

Any guidance on the Alternating Current check on out of the alternator?

[Mopar1973Man]

46 minutes ago, lberch said:

I have the DDRP 2011 vintage (small replacement pump installed where the carter was.

You'll need to consider a better pump and upgrade in plumbing. The stock plumbing measures out at 6mm ID and typical fuel systems ate 3/8" and 1/2" hose. I highly suggest the 1/2" hose over the 3/8". Much better pressure stability. Then the pump should be move back near the fuel tank. No pump is designed to suck a long distance so relocation will help with pump longevity.

48 minutes ago, lberch said:

Any guidance on the Alternating Current check on out of the alternator?

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/28-transmission-systems/260-torque-converter-lock-unlock-issues

Basically taking a good quality DVM that can measure 2 volt or less. Place the RED probe on the BATT of the alternator and the BLACK probe to the case of the alternator or passenger battery ground. Start the truck and let it idle with all loads turned on and measure the voltage.

0.01 to 0.03 is normal

0.05 is marginal - Some report strange random issues. Lock up, etc.

0.1 is fail. Most start seeing failure of computers like ECM with delay wait to start to PSG unit on the VP44 and P1688.

[Buzzinhalfdozen]

7 hours ago, lberch said:

I have the DDRP 2011 vintage (small replacement pump installed where the carter was.

All other lines and hoses are stock.

Understand need an OBII scan reader to reset - thanks

Any guidance on the Alternating Current check on out of the alternator?

I was running a DDRP for a few years mounted on the frame. After I installed a draw straw in the tank and 3/8" fuel line fuel pressure was about 16 cruising and 12psi at wot. 

[Mopar1973Man]

Still a rather wide span of pressure drop. Like Mine is 17 PSI at idle and 15 PSI at WOT. I might drop to 14 PSI in subzero operation. But goes to so how 1/2" lines vs. 3/8 lines are better stablity of pressure. But you also take in the loss on the DDRP I think it what a 100 GPH or 95 GPH vs. my 150 GPH setup.

Edited January 8, 2016 by Mopar1973Man

[Buzzinhalfdozen]

I don't think the DDRP is even rated to move that much fuel. I was just saying it has the potential to be an adequate pump on a mostly  stock engine. I moved on after the second one burned up though. 

[lberch]

So......this AM I checked fuses, grounds, continuity, relays and AC ripple from the alternator as prescribed .05 VAC running with headlights on and Bat+ on alt. and gnd - on alternator housing.

then I bought a scan tool and got P0216 Timing error.  So cycling the ignition three times without starting never gave me the timing code.  I cleared all codes and drove half way home and the truck was fine but reverted to acting back up with P0216 code returning.

So it seems I am needing a pump ......

Is there any value in removing the timing piston and seeing if its stuck and maybe get a little more time? If yes can I do it with the pump installed?  The cover is staring me right in the face.......?

Any input is welcome 

Leo

[Me78569]

The timing piston is removed from the inside of hte pump, so no you can't really do much with it.

 

I did get a few extra weeks out of my pump by running about 2x the amount of 2 stroke as normal and driving the truck HARD once it warmed up.  dunno if driving hard did anything but it did "unstick" for a few weeks.  Then it stuck and failed for good.

[JAG1]

I drove 4 yrs with the 0216 code present using heavy doses of 2 stroke oil.  I started getting hard starts so Moparman changed it out for me. Good Mechanic too.

 

Good to do all the important stuff before a new VP. 1/2'' fuel lines, pump nearer the tank on the frame running off the batteries but controlled by the ECM, fuel pressure gauge to help maintain 15- 20 p.s.i., a filter prior to the lift pump for protection, all screens removed in the tank and a bottle of two stroke ready to go.

I would like to get an AC volt gauge in the truck to help protect all the electronics.

Edited January 9, 2016 by JAG1

[lberch]

Finally replaced the VP44 and all associated codes and dead pedal are gone.  Also installed an Airdog replacement pump and now fuel pressure at idle is 15, normal driving 12 and WOT it still drops to around 6.  Guess I will have to upgrade the supply side hoses to 1/2".  While I was deep into the fuel system I decide to replace the connector tube O-rings.  One of the six looked a little beat up but not much.  I did this because part of my VP44 troubleshooting symptoms was eventually an extended crank start on an incline.

I still have an extended crank first start of the day when it sits over night.  Never had this issue ever before.  I have turned the truck nose down last night to see if it makes a difference.  I guess I am chasing a small air leak that is allowing fuel to be displaced and the extended crank is needed to clear the air at first start?

Any good advise in finding this air leak?

Thanks in advance,

Leo

[dripley]

The return line is a common cause of this. Follow the return line from the VP toward the rear of the engine. It will go into a tee that can leak. It then goes up to the back of the head. The sealing washer on the banjo fitting tends to go bad.  

[BIG-BLACK-DODGE]

On January 25, 2016 at 3:32 AM, lberch said:

Finally replaced the VP44 and all associated codes and dead pedal are gone.  Also installed an Airdog replacement pump and now fuel pressure at idle is 15, normal driving 12 and WOT it still drops to around 6.  Guess I will have to upgrade the supply side hoses to 1/2".  While I was deep into the fuel system I decide to replace the connector tube O-rings.  One of the six looked a little beat up but not much.  I did this because part of my VP44 troubleshooting symptoms was eventually an extended crank start on an incline.

I still have an extended crank first start of the day when it sits over night.  Never had this issue ever before.  I have turned the truck nose down last night to see if it makes a difference.  I guess I am chasing a small air leak that is allowing fuel to be displaced and the extended crank is needed to clear the air at first start?

Any good advise in finding this air leak?

Thanks in advance,

Leo

I have this same problem with my truck as well. My injection pump has 420 some thousand km's. In the morning if i bump the key to run the lift pump in the tank it will usually fire right up. I was thinking i had a onewsy check valve bleeding back somewhere. 

 It only does this if I let it sit all night. Once it starts first thing in the morning it is fine for the whole day so it is definitely like something is bleeding back slowly.

 

 I am getting the exact same fuel pressure as you are as well and I have a new aftermarket "Airtex" stock replacement in tank lift pump and all the stock size lines. 

My  Engine is spotless and I checked all the fuel lines for leaks and I don't feel any wet spots at all back there on those banjo fittings.

Can someone chime in and let us know if there's a one-way check valve in these fuel systems?

 

And i wonder what a BD banjo bolt kit would do for fuel pressure. Maybe it would still have the same idle and cruising pressures but on WOT maybe there would be less drop?? I looked all over but can't find anyone who did this test.

Edited April 7, 2016 by BIG-BLACK-DODGE

[Mopar1973Man]

Got an air leak for sure.

 

Injector o-ring good?

Crossover tube o-rings good?

Pop test the injectors. Do you have any pissy injectors.

Banjo a the back of the head wet?

Suction side leak? Those never leak out. You have to pressurize the fuel tank to get it to leak.

[dripley]

There is no check valve. Once you kill the engine the pressure bleeds off but the lines hold the fuel. An air leak allows the fuel to drain back to the tank.